BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood from the following detailed description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like parts, in which:
FIG. 1 is an enlarged sectional view of a bellows structure for use in an IACV in accordance with an embodiment of the invention.
FIG. 2 is an enlarged sectional view of a pintle for attachment to the bellows structure of FIG. 1.
FIG. 3 is a sectional view of an IACV including the bellows structure of FIG. 1 and the pintle of FIG. 2.
FIG. 4 is a sectional view of an IACV including the bellows structure of FIG. 1 and the pintle of FIG. 2, showing a coil spring biasing the pintle.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
With reference to FIG. 1, a bellows structure, generally indicated at 10, is shown in accordance with the principles of an embodiment of the invention. As shown in FIG. 3, the bellows structure 10 is constructed and arranged to be coupled with a conventional idle air control valve (IACV) 11 for a vehicle. The bellows structure 10 includes a first end 12 defining a base 14, a second, opened end 16, and a bellows 18 between the first and second ends. The base 14 has a periphery 20 that is constructed and arranged to be in press-fit engagement with a recess 22 of a housing 21 of the IACV 11, such that no secondary gluing operation is needed to couple the bellows structure 10 to the IACV 11. The geometry of the bellows 18 prevents inversion under manifold vacuum. The bellows structure 10 is preferably of epichlorohydrin material, having a durometer of about 70 and capable of handling a vehicle temperature range of −40° C. to 125° C. Other materials that are suitable for a vehicle environment can be used for the bellows structure 10. The rubber material for the bellows structure 10 is durable, yet chemically inert to environmental degradation. The bellows 18 can be of any suitable shape, such as conical or cylindrical.
With reference to FIGS. 2 and 3, a pintle 24 is provided to close the opened end 16 of the bellows structure 10. The pintle 24 includes surfaces defining an annular groove 26 therein. The bellows structure 10 includes annular rim member 28, associated with the second opened end 16, which is received (in press-fit engagement) in the groove 26 to retain the pintle 24 to the bellows structure 10. Thus, a first portion 27 of the pintle 24 is received within an internal portion 23 of the bellows structure 10, with a second portion 31 of the pintle 24 extending outside of the internal portion 23 of the bellows structure 10. Assembly is easily performed by simply sliding the annular rim member 28 over the first portion 27 of the pintle 24.
It can be appreciated that no O-rings or secondary radial retention components are needed to secure the pintle 24 to the bellows structure 10. The compression seals of the bellows structure 10 with respect to the housing 21 and pintle 24 are not rigid which allows pressure equalization.
The pintle 24 is coupled with a shaft 29 of the motor 32 of the IACV 11 (FIG. 3). The IACV 11 is preferably of the automotive grade can-stack style stepper motor of the type disclosed in co-pending application Ser. No. 11/882,614, the contents of which is hereby incorporated by reference into this specification.
The bellows structure 10 with pintle 24 attached defines a bellows assembly, generally indicated at 30 in FIG. 3. Thus, the bellows together with the pintle 24 surround the shaft 29 and thus protects the internal components of the IACV from contamination.
FIG. 4 shows another embodiment of a bellows assembly 30′ coupled with a shaft 29 of a motor 32 of an IACV 11. This embodiment is similar to that of FIG. 3, however, a coil spring 34 is provided as part of the assembly 30′. The coil spring 34 biases the pintle 24 in the extended position. Preferably, the bellows 18 defines a generally cylindrical interior space 36 to receive the cylindrical coil spring 34.
Some advantages of the embodiments are:
- 1. Press fit/interference of bellows structure 10 into the housing 21, no secondary adhesive/gluing operation required.
- 2. Press fit/interference into the pintle groove 26, no secondary radial retention components or secondary adhesive/gluing operation required.
- 3. Sliding fit of the bellows structure 10 over the pintle shoulder 27, manufacturing assembly improvement.
- 4. Bellows geometry which prevents inversion under manifold vacuum when IACV is use in the throttle body.
- 5. Bellows geometry which allows use of internal coil spring 34.
- 6. Compression seals to housing 21 and pintle groove 26 are not rigid (e.g., are not glued) which allow pressure equalization.
- 7. Rubber material for bellows structure 10 that is durable yet chemically inert to environmental degradation.
- 8. Rubber material for bellows structure 10 that will remain flexible below freezing temperature. The IACV may loose functionality when the bellows become rigid.
- 9. The bellows structure 10 is a physical barrier which prevents liquid, vapour and/or particulate contamination from entering the IACV. This contamination exclusion will extend the warranty/durability life of the IACV.
The foregoing preferred embodiments have been shown and described for the purposes of illustrating the structural and functional principles of the present invention, as well as illustrating the methods of employing the preferred embodiments and are subject to change without departing from such principles. Therefore, this invention includes all modifications encompassed within the spirit of the following claims.
Patent Application
20080066717
